Friction clutch



May 11, 1943. H. NUTT FRICTION CLUTCH Filed Jan. 16, 1942 f 71222722327firold' Na 23% Patented May 11, 1943 FRICTION CLUTCH Harold Nutt,Chicago, Ill., assignor to Borg- Warner Corporation, Chicago, 111., acorporation of Illinois Application January 16, 1942, Serial No. 426,935

7 Claims.

This invention relates to friction clutch plates, and has as its objectto provide an improved torsional vibration dampening means in a clutchplate.

More particularly, the invention is directed to the type of vibrationdampening mechanism shown in my pending application Serial No. 387,801,in which a Belleville washer spring is employed to develop brakingengagement'between the friction washer and a cooperating member, such asa hub flange, against which the washer is brakingly engaged. In themechanism shown in that application, the Belleville Washer spring servesmerely as a means for developing resilient axial pressure, and apressure plate is interposed between the Belleville spring and theadjacent friction washer, the pressure plate being provided with afinger extending through the Belleville spring and engaging the adjacenthousing plate, so that the pressure plate may be held against rotationwith reference to the housing plate.

The primary object of the present invention is to simplify thatconstruction. To this end, the invention contemplates the elimination ofthe pressure plate, and stressing the washer spring to just the rightextent to develop full surface to surface braking contact between thewasher spring and the adjacent friction washer, whereby the spring notonly maintains its previous function of providing the axial pressure fordeveloping braking engagement between the friction surfaces, but alsothe additional function of coacting with the adjacent friction washer toprovide one of the pairs of braking surfaces.

Another object of the invention is to provide, in a torsional vibrationdampening mechanism in which a Belleville washer type spring isinterposed in series with a friction washer or washers between the hubflange and a housing plate, a form of spring which is by reason of anoncircular periphery, adapted to coact with the cushioning spring ofthe plate so as to be held against rotation with reference to theadjacent housing plates.

Other objects. the advantages and uses of the invention will become moreapparent after reading the following specification and claims and afterconsidera ion of the drawing forming a part of the specification,wherein:

Fig. 1 is an elevation of a portion of a clutch pla e embodying myinvention;

Fig. 2 is an axial sectional view thereof;

Fig. 3 is an enlarged detailed sectional view of the braking mechanism;and

Fig. 4 is a perspective view of a portion of the washer spring.

As an example of one-form in which the invention may be embodied, I haveshown in the drawing a clutch plate comprising a hub l0 havin a radialflange l2 embraced between a pair of spring housing plates l4 and IS.The housing plates 14 and I6 are secured together by rivets i8 whichextend through notches 20 in the periphery of the hub flange l2, and areformed with spring retaining shrouds 22 defining spring openings 24registering with complementaryspring openings or notches 26 in the hubflange l2. In the openings 24 and 26 are seated springs 28 the ends ofwhich are adapted to engage the edges of the housing plates l4 and I6and of the flange l2 defining the openings 24 and 26, so as to form asectional cushioning torque transmitting connection between the hub andthe housing plates.

The housing plate I4 is extended as at 30 to form a facing carrying discto which are riveted, at 32, a plurality of yieldable facing mount ingcushions 34. To the facing mounting cushions 34 are riveted, at 36, apair of facings 38.

Torsional vibration tending to develop between the hub Ill and thefacing carrying disc 30 is absorbed by mechanism comprising frictionwashers and 42 having braking engage ment with friction faces 44 on therespective sides of the hub flange i2. The washer 40 also has brakingengagement with one of the spring housing plates l4, Hi. In thearrangement shown, this engagement is with facing carrying plate N.

The friction washers 40 and 42 receive the hub l0 fairly snugly so as tobe maintained in concentric relationship thereto. Between the frictionwasher 42 and the housing plate I6 is interposed a Belleville washertype spring 46. the inner portion of which has direct braker contactwith the other face of the washer 42, and the outer portion of which isin abutting engagement with the housing plate IS. The in ner portion ofthe housing plate I6 is offset axially away from the washer spring 46 asat 48, the offset defining a shoulderv 50 against which the peripheralportion of washer spring 46 is seated, the remainder of the spring 46being thus spaced from the housing plate I6 so as to restrict thepacking pressure in the dampening means to that which is developed bystressing the washer spring 46.

I have referred to the washers 40 and 42 as though only one washer wereemployed on each side of the flange l2, and Fig. 2, because of the scaleto which it is drawn, only shows a single washer on each side of theflange. Actually, I prefer to employ a plurality of washers in series oneach side of the flange asdisclosed in Fig. 3 in accordance with theinvention set forth in my application Serial No. 348,085, flled July 29,1940, and issued as Patent No. 2,277,558 on March 24, 1942. However, itis to be understood that it is possible to employ the present inventionin connection with a single frictional washer on each side of the hubflange.

Referring now to Fig. 3, the washer spring 46 is of the general typecommonly known as a Belleville washer spring," its normal unstressedform being indicated in dotted lines at 52 in Fig. 3. The presentinvention contemplates the stressing of the spring from this form, inwhich its contact with the washer 42 would be restricted to a circularline contact at the inner edge of the spring, to a flat plane in whichit has full surface to surface contact with the outer face of the outerwasher 42. This engagement between the washer spring and the frictionwasher provides one of the pair of braking surfaces of the dampeningmeans.

Utilization of this pair of braking surfaces is assured by anchoring thewasher spring 46 against rotation relative to the: housing plate l6.While various means of thus anchoring the washer spring might beemployed, the invention contemplates eliminating the use of rivets,lugs, etc. in order to simplify the construction. To this end, theperiphery of the spring is cut away to provide straight sides 54defining between them corners 58 which project between adjacent cushionsprings 28and are adapted to engage the springs in the event of anytendency of the washer springto' rotate relative to the housing plate.

I claim:

1. In a friction clutch, a hub having a radial flange, a pair of annularspring housing plates, one of which is adapted to support frictionfacings, secured together one on either side of said flange, said platesand flange having registering openings, springs seated in said openingsand collectively forming a sectional cushion between said hub andplates, and torsional vibrational dampening means comprising a frictionwasher and a Belleville washer spring interposed in series between saidflange and one of said plates, said washer spring beingin direct contactwith said friction washer and stressed from its normally conical formcapable of having only a circular line contact with said friction washerat one of its edges, to a form in which it has full surface to surfacecontact with said friction washer, whereby to provide one of the pairsof braking surfaces of said dampening means and at the same time toprovide the resilient axial pressure for de'veloping the braking action.

2. In a friction clutch, a hub having a radial flange, a pair of annularspring housing plates, one of which is adapted to support frictionfacings; secured together one on either side of said flange andosoillatably receiving said hub, said plates and flange havingregistering openings, springs seated in said openings and collectivelyforming a sectional cushion between said hub and flange, one of saidplates having an inner region offset axially away from said flange toprovide a shoulder, and torsional vibration dampening-means comprising afriction washer and a Belleville washer type spring interposed oneplate, the inner portion of said spring being in direct contact withsaid friction washer and axially spaced from said offset inner region ofthe plate and the outer peripheryof said washer spring being in abuttingcontact with said shoulder, said washer spring being stressed from itsnormally conical form capable of having only a circular line contactwith said friction washer at its inner edge, to a flat form in which ithas full surface to surface contact with said friction washer, wherebyto provide one of the pairs of braking surfaces of said dampening meansand at the same time to provide yielding axial pressure for developingthe braking action.

3. In a friction clutch plate, a hub having a radial flange providing apair of annular spring housing plates, one of which is adapted tosupport friction faclngs, secured together, one on either side of saidflange, said plates and flange having registering openings, springsseated in said openings and collectively forming a sectional cushionbetween said hub and plates, and torsional vibration dampening meanscomprising a thin flat friction washer snugly receiving said hub and infrictional braking engagement. with said flat flange surface, and aBelleville washer spring interposed between said friction washer and oneof said plates with the inner portion of said spring in direct brakingcontact with said friction washer and the perphery thereof in abuttingcontact with said one plate, in a region radially outwardly of theperiphery of said friction washer, said washer spring being stressedfrom its normally conical form capable of having only a circular linecontact with said friction washer at its inner edge, to a flat form inwhich it has full surface to surface contact with said friction washer,whereby to provide one of the pairs of braking surfaces of saiddampening means and at the same time to provide resilient pressure fordeveloping the braking action.

4. In a friction clutch, a hub having a radial flange provided on oneside adjacent the hub with a flat friction surface, a pair of annularspring housing plates secured together one on either side of saidflange, said plates and flange having registering openings, springsseated in said openings and collectively forming a sectional cushionbetween said hub and plates, and torsional vibration dampening meanscomprising a plurality of thin flat friction washers and a Bellevillewasher spring interposed in series in the order named between saidflange and one of said plates, said friction washers being piloted uponthe hub with the inner washer in braking contact with said flangesurface and the outer washer in direct braking contact with the innerportion of said washer spring, the outer portion of said washer springprojecting radially beyond said washers and being in abutting contactwith said one plate, said washer spring being stressed from its normallyconical form capable of having only a circular line contact with saidouter friction washer at its inner edge, to a flat form in which it hasfull surface to surface contact with the outer face of said outerfriction washer, whereby to provide one of the pairs of braking surfacesof said dampening means and at the same time to provide resilient axialpressure for developing the braking action between all of the frictionsurfaces.

5. In a friction clutch plate, a pair of annular members, one of whichis adapted to carry friction facings and a hub having a radial flangemember,

flat friction surface, a,

said pair or members comprising spring housing plates secured togetherone on either side of the third member and being provided withregistering windows, springs seated in said windows and collectivelyforming a sectional cushion between said hub and facing carrying member,and. torsional vibration dampening means interposed between another twoof said members, said dampening means including a friction washer and aBelleville washer spring interposed in series between said other twomembers, said washer spring having a non-circular periphery adapted tointerenga e with said cushion springs so as to hold said washerspringagainst rotation relative to said other two members.

6. In a friction clutch plate, a pair of annular members,- one of whichis adapted to carry friction facings and a hub having 'a radial flangemember, said pair of members comprising spring housing plates securedtogether one on either side of the third member and being provided withregistering windows, springs seated in said windows I and collectivelyforming a sectional cushion between said hub and facing carrying member,and torsional vibration dampening means interposed between another twoof said members. said dampening means including a friction washer and aening means interposed between said members,

said dampening means including a friction washer and a Bellevilie washerspring in Q p ed in series between said members, said washer springbeing in direct braking contact with said friction washer and stressedfromits normally conical shape capable of having only a circular linecontact with said friction washer at one of its edges, to a form inwhich it has full surface to surface contact with said friction washer,whereby to provide one of the pairs of braking surfaces of saiddampening means and at the same time to provide resilient axial pressurefor developing the braking action..

' HAROLD NU'II.

